Mr Tilney also refused to testify before the Senate

Embattled investment-banking firm Merrill Lynch has fired two executives for failing to testify before US law-enforcement agencies about their role in the Enron accounting scandal.

Merrill said it terminated vice chairman Thomas W Davies and Schuyler Tilney, a managing director in investment banking.

Both men declined to testify in an investigation by the Securities and Exchange Commission (SEC) and the US Department of Justice into financial transactions initiated by Enron in 1999.

In a written statement, the company said "while it regretted the action, it was enforcing its policy requiring employees to fully co-operate with regulatory and law enforcement investigations".

High profile sackings

The company said it was not aware of any wrongdoing on the part of its employees.

Mr Davis' attorney, Thomas Fitzpatrick, said his client was innocent and defended his right to take the Fifth Amendment, referring to the constitutional right against self incrimination.

"The collapse of Enron has caused the Department of Justice to launch criminal investigations into legitimate financial transactions involving Enron and Merrill Lynch," Mr Fitzpatrick said.

"There are no new facts, and Merrill Lynch has been consistent in stating that it's not aware of any evidence that its employees acted improperly in their dealings with Enron," said Mr Tilney's lawyer, Robert Trout.

"Mr. Tilney did not do anything improper," he said.

Mr Tilney had been placed on administrative leave in July for failing to testify to before a Senate subcommittee about Enron's collapse.

Mr Davies was set to retire in November after 25 years of service.

The dismissals are significant because the men are the highest-ranking executives to lose their jobs over their work with Enron.